REPORT: There's a reason all crash test dummies were male until last year.

Last year, government regulators made female crash test dummies a mandatory part of crash evaluations for the first time in collision evaluation history. Until then, manufacturers had been content to use dummies patterned after the average American male.

Safety advocates have argued for years that designing for male occupants present problems for smaller females. When airbags deploy, they're meant to strike occupants in the chest, but smaller individuals may instead be hit in the chin. If that happens, further head and neck injuries could ensue. According toAutomotive News, smaller women are three times as likely as average-sized male drivers to be seriously injured in accidents.

Automakers have repeatedly argued that the average-sized test mannequin covers 95 percent of the driving population, and that developing a smaller dummy would take too long to create and be cost prohibitive. That argument has officially fallen by the wayside with the new requirements. Automotive News reports manufacturers are officially required to use small female crash dummies in front collision evaluations for 2011 model-year units.